TR5 Welding Preview

Building Engineering Services Association Guide to good practice:WELDING OFCARBON STEELPIPEWORK TR/5 www.theBESA.com

Building Engineering Services Association Guide to good practice: AcknowledgmentsWELDING OF Members of drafting panel who have given their time,CARBON STEEL knowledge and experience in the compiling of thisPIPEWORK publication. TR/5 Mr Alan Rodgers Mr Eddie Scott Mr John Cassidy Mr Dave Lewin Mr Alan Keating - Secretary This Code of Practice is issued by the Building Engineering Services Association and supersedes: ‘Recommended Practice and tests for Certificates of C ompetency for Oxy-Acetylene and Metal-Arc Welds in Mild Steel Pipework’ first published by the HVCA (now BESA) in 1970; and previous publications on this subject. ISBN 00-903783-50-9 First published 1980 and revised in 1990 ©2003 BESA BESA Publications Old Mansion House Eamont Bridge Penrith CA10 2BX 01768 860405 [email protected]. www.theBESA.com

Building Engineering Services AssociationGuide to good practice: ForewordWELDING OF This publication is intended to set the standards for the welding of carbonCARBON STEEL steel pipework. This is part of a suite of publications, which forms the basisPIPEWORK for an assessment regime introduced by the Building Engineering Services Association, by which the competence of new and existing TR/5 members’ can be evaluated. THIS CODE OF PRACTICE relates to the welding of carbon steel pipework only. It deals with water, steam and gas pipework at pressures up to and including 17.0 bar and/or temperatures from -20°C up to and including 220°C. The tests and requirements specified take account of current practice and are in accordance with British Standard Specifications 2640 and 2971 so far as they relate to the welding of pipework within the scope of this code of practice. The tests given in this manual are the accepted standard for the issue of welder approval certificates by Engineering Services Training Trust Limited (ESTTL) on behalf of the Building Engineering Services Association (BESA). Compliance with this Code of Practice does not confer immunity from any legal obligations. www.theBESA.com

Welding of Carbon Steel Pipework – Code of PracticeCONTENTSINTRODUCTION Page 3Section 1 SCOPE 7 72 CONFORMITY WITH LAW OR REGULATION 8 83 PARENT METAL 9 94 WELDING CONSUMABLES & SHIELDING GASES 105 WELDING PROCESSES 116 WELDING EQUIPMENT 11 127 PREPARATION OF PIPE ENDS FOR BUTT WELDS 12 Sizing of pipes 13 Matching and expanding Methods of preparation 13 148 BRANCHES Branch reinforcement 14 (Compensation)9 REDUCERS10 BENDS, SETS AND EX PANSION LOOPS11 ANCHORS, GUIDES AND ATT ACHMENTS12 FLANGES Slip-on Flanges Weld Neck Flanges13 NON-RECOMMENDED PRACTlCES14 HEAT TREATMENT Pre-heating Post weld heattreatment15 VISUAL EXAMINATION OF WELDED JOINTS Profile of weld Surface nish Freedom from undercut Root penetration and concavity Cracks 4

Welding of Carbon Steel Pipework – Code of Practice16 PRODUCTION WELDS Non- Page destructive examination 15 Destructive examination17 HYDROSTATIC TESTS 1518 STANDARD OF WORKMANSHIP 16 Supervision Surface preparation Procedure Welder identi cation19 WELDER APPROVAL 16 Welder approval certi cates Validity of certi cateA PPENDICESAppendix I Standard Tests for Welder Approval 23Appendix II Examination of Test Pieces 25Appendix III Non Destructive Examination 25 27Glossary of Referenced Standards PublicationsILLUSTRATIONSFigure 1 Typical preparations for butt welding 10Figure 2 90° Unequal Set-on Branch Preparation for Oxy-Acetylene Welding 17Figure 3 90° Unequal Set-on Branch Preparation for Manual Metallic Arc Welding 17 and Gas Shielded Arc WeldingFigure 4 90° Unequal Set-on Branch Preparation, without gap, for water at ambient 18 temperature up to 10 bar only.Figure 5 Curved or easy sweep Set-on branch joint 18Figure 6 Weld Neck Flange. 19Figure 7 Slip-on Bossed Flange. 19Figure 8 Slip-on Plate Flange. 19Figure 9 Minimum height of Flanged Branches 20Figure 10 Satisfactory and Unsatisfactory Butt Weld Pro les. 20Figure 11 Satisfactory and Unsatisfactory Branch Weld Pro les. 21Figure 12 Testpiece No.1 - pipe welded in vertical position. 24 5

Welding of Carbon Steel Pipework – Code of Practice Figure 13 Testpiece No.2 - pipe welded in horizontal position. Page Figure 14 Testpiece No.3 - pipe welded in xed 45° inclined position 24 Figure 15 Bend Test Detail 24 246